V6 misfiring badly + lack power!!!

Hi Stang Fan,
I’m stunk with a weird problem that I didn’t find any solution on the Forum for it! I have a 1995 Mustang V6 with automatic transmission (180 000 km) and it’s been 3 months now that the engine is misfiring or idle rough + terrible lack of power. It all started with the car sitting in the garage for about 2 weeks without moving (was off on vacation). When we came back, the car would start find without any apparent problem and after a couple of minutes it started misfiring and the engine was sacking badly. On top of that the Tach indication isn’t realistic, was getting an RPM of 800 with full throttle applied (in my mind was more up to 3 000 or 3 500 RPM!!!) + the Tach needle was moving up and down eracticly. I went and filled the tank up thinking that some condensation might have happened in the gas tank and I was getting water in the fuel, no luck…same problem! :shakehead

I then found the spark plug wire were leaking a bit (I’ve change them only 6 months before but they were bad again, got them exchange under the warranty)…no luck again.:uhoh:
I was receiving an MIL code which a local garage read for me, P0302 (Cylinder 2 Misfire Detected). I’ve changed the number 2 spark plug (which also got replace 6 months ago but sh*t happen!). No positive result. Got the Coil pack and the trigger harness tested and found it ok but desperate to find the solution, I’ve changed the coil pack anyways with a used one (changed it twice actually :screwy:) No positive result either. :disappoin
I’ve took all the spark plug off and got a compression check done, compression is ok (the previous owner told me that he got the head gasket job done but I wanted to verify if a valve wasn’t stuck!). I inspected the spark plug and found them to all have heavy carbon deposit on them (Soft, black, sooty, dry-looking carbon… not oil deposit!). This is usually a sign of a rich air/fuel mixture or poor misfiring. Having this heavy carbon deposit, it’s easy to see which sparkplug is firing (only one shiny point on the plug were the spark comes out), found that spark plug at cylinder #1 wasn’t firing… replace it…guess what…no change! :frown:
I though maybe the PCM isn’t receiving the correct crankshaft position signal and this is why I have rich air/fuel mixture and bad Tach reading. So I changed the Crankshaft position sensor… no change! :shakehead
Seeking for a vacuum leak with a spray bottle with a mixture of water and soap, I found that the fuel injector o-ring where leaking. Change all injector o-ring + plenum intake gasket, also cleaned the air intake, EGR valve (+exhaust connecting tube) and IAC valve with a special cleaner… No changes!!!:banghead:
I don’t know what is left to do!!! Change the PCM or the ignition module, maybe the camshaft position sensor?!? Drive the f**king car into a ditch :grinyes: ! Did I miss something!!!
Please Help

My son's 2000 has the exact same probelm.. even same cyl listed as missing.
He replaced the coil, plug wires.. then it got wierd.
It ran still missing, them died, them after sitting for an hour or so ran fine.
Then back to misire on all cylinders.
PLEASE help me.
I dont want to get him a new car.
Oh the mustang is a 2000 auto tranny, v6, about 180k miles on it.

Thanks

Psycocavr

:banghead:
I know how that can be. This might not help but it is a good start towards your problem. I had a few cars have this problem and it turned out to be the mass airflow sensor on the air intake box right have the ai filter. To check to see if this piece is out, disconnect the electrical connecter that plugs in to it. Your car should run fine after this. It is does then you will have to replace that piece. The car will run fine, but the check engine light will be on. This happened with my mustang and all I did was unplug i for like an hour of running it and then plugged it back in and had no problems since. It took me that long to go into the next major city to get it. You will want to get the part as soon as possible. Prolonging it and running the car like that will lead to more problems. See if this helps. Sorry I did not get to it sooner

This might be worth a shot. I have a 1999 Windstar van AND a 1995 Mustang with the same 3.8L V6. On my Windstar recently, I was chasing this same code, replacing the same parts that you mention, to no avail. On this forum and others, frequent mention is made of plugged EGR ports being plugged with gunk causing this and other problems. The intake manifold has to be removed to access the EGR ports (one port for each cylinder ). When I inspected mine, 5 of the six were completely plugged, and one was partially plugged. After cleaning, it ran like a top! After fixing the van (130K miles), I ran some carb cleaner through the Mustang (100K miles) as a preventative. Someday when I have time, I plan on inspecting the EGR port on the Mustang to see how they are doing. This is a VERY common problem on the 3.8L Windstars. I would imagine that the Mustang could be hindered by it, also.